Question

How to check if string is empty in C

Answer 1

#include <stdio.h>
#include <string.h>

#define SIZE 16

int StringIsEmpty(char s[], int size);

int main(void)
{
	char s[SIZE] = "That Code!";
    
    if (StringIsEmpty(s, SIZE))
        printf("Empty\n");
    else
        printf("NOT Empty\n");
    
    memset(s, '\0', sizeof(s));
    if (StringIsEmpty(s, SIZE))
        printf("Empty\n");
    else
        printf("NOT Empty\n");

    return 0;
}

int StringIsEmpty(char s[], int size)
{
    int i = 0, count = 0;
    
    while (s[i++] == '\0') count++;
    
    return size == count;
}
 
/*
run:

NOT Empty
Empty

*/

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Answer 2

#include <stdio.h>

#define SIZE 32

int main(void)
{
	char s[SIZE] = "That Code!";
      
    if (s[0] == '\0')
        printf("Empty\n");
    else
        printf("NOT Empty\n");
		
	s[0] = '\0';
	if (s[0] == '\0')
        printf("Empty\n");
    else
        printf("NOT Empty\n");
     
    return 0;
}
  
    
/*
      
run:

NOT Empty
Empty

*/

 

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Answer 3

#include <stdio.h>
#include <string.h>

#define SIZE 32

int main(void)
{
	char s[SIZE] = "";
	
	if (strcmp(s, "") == 0)
        printf("Empty\n");
    else
        printf("NOT Empty\n");
     
    return 0;
}
  
    
/*
      
run:

Empty

*/

 

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Answer 4

#include <stdio.h>

#define SIZE 32

int main(void)
{
	char s[SIZE] = "";
	
	printf("Enter a string: "); // Ctrl + c = Empty
	if (scanf("%s", s) == -1)
        printf("Empty\n");
    else
        printf("NOT Empty\n");
     
    return 0;
}
  
    
/*
      
run:

Enter a string: Empty

*/

 

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